The present invention relates to a door especially to a door for motor vehicles. In such a door a central core extends between the door hinges and the door lock and forms a carrier for the interior and exterior door means such as door panels. German Patent Publication (DE-AS) No. 1,480,089 discloses such a door, for example, in which the central door member forms a Y-shaped or V-shaped carrier arrangement. These doors have, among others, the advantage that the interior and exterior door components such as door panels may be made of synthetic material without regard to any force transmitting capabilities of these interior and exterior door means. Thus, these interior and exterior door means may be constructed as covering panels exclusively. Such a structure results in a substantial weight reduction but has the disadvantage that the strength of the entire door structure is necessarily reduced. Thus, this type of door cannot normally meet the requirement for a maximum reduction of any dangers to passengers in a motor vehicle resulting from a lateral impact and causing a deformation of such doors.